package com.itzb.asone.utils;

import java.security.MessageDigest;

public class CipherUtil {

	private final static String[] HEXDIGITS = { "0", "1", "2", "3", "4", "5","6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

	/**
	 * 对字符串加密
	 * @param inputString 输入字符串
	 * @return 
	 */
	public static String generatePassword(String key,String inputString) {
		return encodeByMD5(inputString + key);
	}

	/**
	 * 验证密码
	 * @param password 加密密码
	 * @param inputString 输入字符串
	 * @return
	 */
	public static boolean validatePassword(String key,String password, String inputString) {
		if (password.equals(encodeByMD5(inputString + key))) {
			return true;
		} else {
			return false;
		}
	}

	private static String encodeByMD5(String originString) {
		if (originString != null) {
			try {
				// 创建具有指定算法名称的信息摘要
				MessageDigest md = MessageDigest.getInstance("MD5");
				// 使用指定的字节数组对摘要进行最后更新，然后完成摘要计算
				byte[] results = md.digest(originString.getBytes());
				// 将得到的字节数组变成字符串返回
				String resultString = byteArrayToHexString(results);
				return resultString.toUpperCase();
			} catch (Exception ex) {
				ex.printStackTrace();
			}
		}
		return null;
	}

	private static String byteArrayToHexString(byte[] b) {
		StringBuffer resultSb = new StringBuffer();
		for (int i = 0; i < b.length; i++) {
			resultSb.append(byteToHexString(b[i]));
		}
		return resultSb.toString();
	}

	private static String byteToHexString(byte b) {
		int n = b;
		if (n < 0)
			n = 256 + n;
		int d1 = n / 16;
		int d2 = n % 16;
		return HEXDIGITS[d1] + HEXDIGITS[d2];
	}

	
	public static void main(String[] a) {
		String input = "123456";
		String password = generatePassword("zhangbin",input);
		System.out.println(password);
		System.out.println(validatePassword("root",password, "123456"));
	}
}
